Molecular Characterization of Hemoglobins Kurosaki [α7 Lys→Glu], G-Pest [α74 Asp→Asn], Stanleyville-II [α78 Asn→Lys] and J-Rovigo [α53 Ala→Asp]

α-chain hemoglobin variants with electrophoretic mobility similar to that of hemoglobin S in newborn screening programs

“…The former include Hbs D, Lepore, Korle-Bu, Osu-Christiansborg and Zürich (13,14) , and the latter Hbs Hasharon, Stanleyville-II, G-Pest, Sunshine Seth, G-Philadelphia, West One and Daneshgah-Tehran (8,9,14) . In the case of the α-chain variants, some technical characteristics can help with the diagnosis; these include the presence of four bands in electrophoresis - two corresponding to Hb A 2 (A 2 and A 2 ') and two to Hb A (A and 'X') - and a lower concentration of 'Hb X' than normally observed in individuals with β-chain variants.…”

“…In the case of Hb S in association with other variants, whether Hb S-like or not, correct identification of the second variant is fundamental to distinguish between those variants that will lead to SCD, those that evolve without any symptoms and those that produce specific symptoms (7) . Molecular techniques, such as restriction enzyme analysis and globin gene sequencing, are the most commonly used techniques for known mutations and new or rare mutations, respectively (8,9) . It should also be mentioned that some Hb S-like variants can cause red blood cell sickling, hemolysis and vaso-occlusion even in a heterozygous state.…”